To flexibly configure an operation environment capable of easily and efficiently setting data processing in accordance with settings of expansion functions for a composite function while visually confirming the expansion functions of devices, a system configuration is displayed on a CRT in accordance with function information, connection information and status information of each device acquired via a network. When a user designates a set of icons of devices for realizing desired composite function processing, a CPU operates to display a combination function setting screen for the composite function processing, and displays on this setting screen a configuration image including the designated expansion functions of devices. A combination operation of corresponding devices is controlled in accordance with the settings on the setting screen.